She leaned back. The archivist, Elias Ward, had been obsessed with medieval ciphers. She’d found a notebook in his flat with scribbled notes: “Vigenère key = ELIAS” . Her heart jumped.

She kept the letter pinned to her board. Years later, a linguist friend deciphered it by accident while cleaning old files: it was a simple (or Caesar shift +19, which is equivalent to -7). Decoding: d(4)-7=23→w, a(1)-7=20→u, n(14)-7=7→h, l(12)-7=5→e, w(23)-7=16→p, d(4)-7=23→w → “w u h e p w” → “where” — wait, “where” is w-h-e-r-e. Close: “wuhepw” is off by a letter. So maybe a typo in the original? But the rest: wy(23,25)-7=(16,18)→p,r → “pr” py(16,25)-7=(9,18)→i,r → “ir” an(1,14)-7=(20,7)→t,g? No.

Maybe it’s ? No.

Her intern, Leo, suggested a simple shift. “ROT13?” he asked, typing it in. Gibberish. “Atbash?” More nonsense. “Maybe it’s reversed?” Mira reversed the string: nwfya yarb yn ja a hsm na yp wy dwlnad . Nothing.

Now reverse the whole string: “ajsln lneo lw an nfuz an lc jl qnayjq” — still gibberish.